CN108046903B

CN108046903B - Disintegrating magnesium-containing granulated fertilizer and preparation method thereof

Info

Publication number: CN108046903B
Application number: CN201711335268.0A
Authority: CN
Inventors: 李红; 杨云洪; 李长龙; 车太龙
Original assignee: Yingkou Magnesite Chemical Ind Group Co ltd
Current assignee: Yingkou Magnesite Chemical Ind Group Co ltd
Priority date: 2017-12-08
Filing date: 2017-12-08
Publication date: 2021-06-18
Anticipated expiration: 2037-12-08
Also published as: CN108046903A

Abstract

The invention relates to the technical field of agricultural fertilizers, and particularly provides a disintegrating type magnesium-containing granulated fertilizer and a preparation method thereof, wherein the magnesium-containing fertilizer granules comprise the following raw materials in parts by mass: 60-90 parts of magnesium-containing raw material; 10-40 parts of a balling assistant; 12-20 parts of organic acid solution with the mass concentration of 5% -20%. The disintegration type magnesium-containing granular fertilizer provided by the invention has the characteristics of short disintegration time limit, high disintegration rate, smooth and uniform granules and high hardness, and the disintegration type magnesium-containing granular fertilizer can be quickly disintegrated or dissolved when meeting water or tide due to good disintegration performance, so that the utilization rate of nutrients in crops in soil is improved, and the growth promoting effect is good; the preparation method of the disintegrating magnesium-containing granulated fertilizer has the advantages of simple production process, low cost, convenience for mechanical fertilization and reduction of environmental pollution.

Description

Disintegrating magnesium-containing granulated fertilizer and preparation method thereof

Technical Field

The invention relates to the technical field of agricultural fertilizers, in particular to a disintegrating type magnesium-containing granular fertilizer and a preparation method thereof.

Background

Magnesium is a necessary medium nutrient element for crops, is a component of chlorophyll and can promote photosynthesis; is an activator of a plurality of enzymes, can promote the synthesis of various substances, thereby improving the quality of fruits and vegetables and playing an important role in plant nutrition; the magnesium is suitable for various crops and soil with phosphorus deficiency, and is particularly suitable for acid red soil with serious magnesium leaching in south.

Magnesium fertilizer belongs to medium element fertilizer, for a long time, only large amount of elements (nitrogen, phosphorus and potassium are NPK for short) are applied, while the application of medium elements is ignored, so that the improvement of the yield and the quality of crops is limited, and in recent years, the reasonable application of medium element fertilizer is more and more important along with the gradual conversion from quantity to quality of the requirements of people on agricultural products.

The domestic traditional magnesium fertilizer mainly comprises brucite, magnesite, light burned magnesium and magnesium sulfate, particularly brucite, because of rich resources and low cost, the magnesium fertilizer is applied to a large amount of fertilizers and is used for supplementing medium elements required by crops; brucite powder (the main component is magnesium hydroxide) is white powder, which is difficult to be applied uniformly and pollute the environment; meanwhile, the brucite powder cannot meet the requirements of high granulation rate, high strength and good disintegration performance of the granulated fertilizer, and is still in a granular state without disintegration for three months, half a year or one year when being applied to soil, so that the brucite powder is extremely low in utilization rate of crops in the soil and is limited in application. Therefore, the disintegration performance of the magnesium-containing fertilizer is the basic requirement that the available nutrients of the fertilizer can release or improve acid soil,

in the aspect of fertilizers, the disintegration means that the granulated fertilizer is applied into soil and can be disintegrated or dissolved when meeting water or tide; the disintegration time limit refers to the time required for the granulated fertilizer to pass through a screen after being completely disintegrated and dispersed or being crushed in water by a specified method; the disintegration rate is the ratio of the amount of the granulated fertilizer disintegrated and dispersed in water to the amount of the granulated fertilizer put into the water. Although no specific index is specified on the aspect of the fertilizer about the disintegration time limit and the disintegration rate, the good disintegration performance is one of the basic characteristics for ensuring the nutrient release of the fertilizer, and the method has great significance for fully exerting the application value of the granular fertilizer containing magnesium.

In the prior art: chinese patent CN1014513096A discloses a method for preparing a magnesium-containing granulated fertilizer, which has the disadvantages that the method only solves the preparation method of the magnesium-containing granulated fertilizer, the disintegration performance of the magnesium-containing granulated fertilizer is not described, and the production process is complex and the cost is high; chinese patent CN 1785914A discloses a brucite granulated fertilizer and a preparation method thereof, and the defects of the brucite granulated fertilizer are that the disintegration time limit of the granulated fertilizer is not described, the disintegration performance is poor, and the fertilizer is single in functionality; chinese patent CN106220338A discloses a disintegrating agent for producing granulated mineral fertilizer, which realizes the disintegration of fertilizer granules by adding the disintegrating agent, so that the content of effective ingredients of the fertilizer is reduced, the utilization rate of the fertilizer is reduced, and the production cost is high; chinese patent CN102775220A discloses a disintegrable round granular sulfur-magnesium fertilizer and a preparation method thereof, and the defects are that the quick-acting performance is poor, the content of magnesium oxide is low, and the fertilizer functionality is too single.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a disintegrating magnesium-containing granulated fertilizer and a preparation method thereof, wherein the magnesium-containing granulated fertilizer has the advantages of short disintegration time limit, high disintegration rate, quick and long-acting performance, good growth promoting effect, soil conditioning function, simple production process and low cost.

Therefore, the invention provides a disintegrating magnesium-containing granulated fertilizer, wherein the magnesium-containing fertilizer granules comprise the following raw materials in parts by mass: 60-90 parts of magnesium-containing raw material; 10-40 parts of a balling assistant; 12-20 parts of organic acid solution with the mass concentration of 5% -20%. The disintegration type magnesium-containing granular fertilizer provided by the invention belongs to a secondary element fertilizer.

Further, the magnesium-containing raw material component comprises: brucite powder (magnesium is calculated by MgO), and the MgO mass content is more than or equal to 64 percent; dolomite powder (magnesium is calculated as MgO), and the mass content of MgO is more than or equal to 21 percent. In the magnesium-containing raw material component, the mass ratio of brucite powder to dolomite powder in the magnesium-containing raw material is (4-5) to 1, and the dolomite powder is added, so that the acidity of the soil can be improved, the physical properties of the soil can be improved, the nitrification of the soil can be enhanced, and the conversion of soil ammonium nitrogen to nitrate nitrogen can be promoted.

Further, the auxiliary agent for balling is magnesium sulfate monohydrate (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 29 percent; magnesium oxide (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 85 percent; magnesium carbonate (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 35 percent; magnesium chloride (magnesium is calculated as MgO), and the MgO mass content is more than or equal to 29 percent. The added pelletizing assistant improves the adhesive property of the material surface and enhances the agglomeration, thereby being easy to pelletize and improve the strength. In addition, effective magnesium can be provided without introducing other substances, the content of magnesium oxide is high, the utilization rate of the fertilizer is improved, and the fertilizer has quick-acting property and long-acting property.

Further, the organic acid solution is any one or more of formic acid, acetic acid, oxalic acid, propionic acid, butyric acid and dimeric aspartic acid.

In addition, the invention also provides a preparation method of the disintegrating magnesium-containing granulated fertilizer, which comprises the following steps:

(1) preparing raw materials: respectively measuring a magnesium-containing raw material and a balling assistant component according to the raw material proportion; dissolving organic acid in water to prepare an organic acid solution with the mass concentration of 5-20%;

(2) wetting treatment: putting the magnesium-containing raw material uniformly mixed in the step (1) into a pelletizing granulator, spraying the organic acid solution prepared in the step (1) in a spraying mode in the running process, and carrying out wetting and acidifying treatment; the magnesium-containing raw material component is subjected to wetting treatment, so that a liquid coating film can be formed on the surface of the powder, the powder is subjected to wetting nucleation, the powder is more favorable for powder pelletizing and granulation under the action of mechanical force and capillary force, and the pelletizing rate can be improved.

(3) Pelletizing and granulating: alternately adding the balling auxiliary agent prepared in the step (1) and spraying an organic acid solution on the basis of the step (2), and balling and granulating to obtain round granular materials;

(4) pre-drying: uniformly placing the round granular materials obtained in the step (3) in a belt dryer at the temperature of 100-150 ℃ for static pre-drying for 10-15min, and removing the surface moisture of the granular materials;

(5) drying: placing the pre-dried round granular material in the step (4) into a boiling dryer, and drying at the temperature of 250-300 ℃ for 15-20min until the moisture content is less than 1%;

(6) and (3) post-treatment: and (5) cooling and screening the round granular materials obtained after drying in the step (5) to obtain the disintegrated magnesium-containing granular fertilizer with the grain diameter of 2-4 mm.

And (4) and (5) adopting a combination mode of static drying and dynamic drying, firstly carrying out static belt type pre-drying treatment on wet granules, removing moisture on the surfaces of the granular materials, and preventing the granular materials from generating the phenomena of granule pulverization, cracks and even crushing in the dynamic boiling drying link.

The invention has the beneficial effects that: the disintegration type magnesium-containing granular fertilizer provided by the invention has the characteristics of short disintegration time limit, high disintegration rate, smooth and uniform granules and high hardness, the disintegration type magnesium-containing granular fertilizer can be quickly disintegrated or dissolved when meeting water or tide due to good disintegration performance, the utilization rate of nutrients in soil by crops is extremely high, and the growth promoting effect is good; the method changes the single characteristic that the traditional magnesium-containing granulated fertilizer only contains brucite, has quick-acting and long-acting fertilizing functions, and meets the requirements of the whole growth cycle of crops on nutrients; the soil conditioner has a soil conditioning function, so that the pH value of the soil is kept between 6 and 7, the nitrification of the soil can be enhanced, and the conversion of soil ammonium nitrogen to nitrate nitrogen is promoted; the preparation method of the disintegrating magnesium-containing granulated fertilizer has the advantages of simple production process, low cost, convenience for mechanical fertilization and reduction of environmental pollution.

Drawings

FIG. 1 is a graph comparing the effect of water-disintegrable dissolution of a disintegrated magnesium-containing granulated fertilizer (1-1) provided in example 1 of the present invention with the effect of water-dispersible of a conventional disintegrated magnesium fertilizer (1-2);

FIG. 2 is a graph comparing the effect of water-disintegrable dissolution of the disintegrated magnesium-containing granulated fertilizer (2-1) provided in example 2 of the present invention with the effect of water-dispersible of the conventional disintegrated magnesium fertilizer (2-2);

FIG. 3 is a graph comparing the effect of water-disintegrable dissolution of the disintegrated magnesium-containing granulated fertilizer (3-1) provided in example 3 of the present invention with the effect of water-dispersible of the conventional disintegrated magnesium fertilizer (3-3);

FIG. 4 is a graph showing the content of exchanged magnesium in soil according to the present invention in test example 2 using different fertilization treatments.

Detailed Description

The invention is further elucidated with reference to the drawings and the detailed description.

Example 1:

the embodiment provides a disintegrating magnesium-containing granulated fertilizer which is prepared according to the following mixture ratio and method: (1) preparing raw materials: taking 80kg of magnesium-containing raw materials (wherein 65kg of brucite powder and 15kg of dolomite powder) and uniformly mixing, and taking 20kg of balling auxiliary agents (wherein 17kg of monohydrate magnesium sulfate powder and 3kg of magnesium carbonate powder) and uniformly mixing; dissolving oxalic acid in water to prepare 12kg of oxalic acid solution with the mass concentration of 20%;

(2) wetting treatment: putting the magnesium-containing raw material uniformly mixed in the step (1) into a pelletizing granulator, spraying the organic acid solution prepared in the step (1) in a spraying mode in the running process, and carrying out wetting and acidifying treatment;

(3) pelletizing and granulating: alternately adding the balling auxiliary agent prepared in the step (1) and spraying an organic acid solution on the basis of the step (2), and balling and granulating to obtain round granular materials; the inclination angle of the balling disc is 30 degrees, and the rotating speed is 35-40 r/min;

(4) pre-drying: uniformly placing the round granular materials obtained in the step (3) in a belt dryer at the temperature of 120 +/-2 ℃ for static pre-drying for 15min, and removing the surface moisture of the granular materials;

(5) drying: putting the pre-dried round granular material in the step (4) into a boiling dryer, and drying at 250 +/-2 ℃ for 20min until the water content is less than 1%;

The detection result of the disintegrating magnesium-containing granulated fertilizer obtained by the method is as follows: 63% of MgO content, 0.32% of water content, 14N of hardness, 22s of disintegration time and 100% of disintegration rate.

Referring to fig. 1, fig. 1 is a comparison graph of the effect of the disintegration-type magnesium-containing granular fertilizer provided in this embodiment and the effect of the conventional disintegration-type magnesium fertilizer after being dissolved in water for 60 seconds, and as can be seen from the comparison graph, the disintegration-type magnesium-containing granular fertilizer provided in this embodiment has better disintegration performance than the conventional disintegration-type magnesium fertilizer, and disintegrates or dissolves rapidly after being mixed with water.

Example 2:

the embodiment provides a disintegrating magnesium-containing granulated fertilizer which is prepared according to the following mixture ratio and method:

(1) preparing raw materials: taking 85kg of magnesium-containing raw materials (70 kg of brucite powder and 15kg of dolomite powder) and uniformly mixing, and taking 15kg of balling auxiliary agents (10 kg of magnesium sulfate monohydrate powder and 5kg of magnesium oxide powder) and uniformly mixing; dissolving oxalic acid in water to prepare 15kg of oxalic acid solution with the mass concentration of 15%;

The detection result of the disintegrating magnesium-containing granulated fertilizer obtained by the method is as follows: the detection result is as follows: MgO content of 65%, moisture content of 0.34%, hardness of 12N; the disintegration time limit is 20s, and the disintegration rate is 100%.

Referring to fig. 2, fig. 2 is a comparison graph of the effect of the disintegration-type magnesium-containing granular fertilizer provided in this embodiment and the effect of the conventional disintegration-type magnesium fertilizer after being dissolved in water for 60 seconds, and as can be seen from the comparison graph, the disintegration-type magnesium-containing granular fertilizer provided in this embodiment has better disintegration performance than the conventional disintegration-type magnesium fertilizer, and disintegrates or dissolves rapidly after being mixed with water.

Example 3:

(1) preparing raw materials: taking 90kg of magnesium-containing raw material (wherein 75kg of brucite powder and 15kg of dolomite powder) and uniformly mixing, and taking 10kg of balling auxiliary agent (wherein 5kg of magnesium sulfate monohydrate powder and 5kg of magnesium chloride powder) and uniformly mixing; dissolving oxalic acid in water to prepare 16kg of oxalic acid solution with the mass concentration of 10%;

The detection result of the disintegrating magnesium-containing granulated fertilizer obtained by the method is as follows: 61% of MgO, 0.21% of water, 15N of hardness, 24s of disintegration time and 100% of disintegration rate.

Referring to fig. 3, fig. 3 is a comparison graph of the effect of the disintegration-type magnesium-containing granular fertilizer provided in this embodiment and the effect of the conventional disintegration-type magnesium fertilizer after being dissolved in water for 60 seconds, and as can be seen from the comparison graph, the disintegration-type magnesium-containing granular fertilizer provided in this embodiment has better disintegration performance than the conventional disintegration-type magnesium fertilizer, and disintegrates or dissolves rapidly after being mixed with water.

Test example 1: determination of disintegration time

The test measures the disintegration time limit of the disintegrated magnesium-containing granulated fertilizer prepared by the invention, wherein the test is carried out by taking the disintegrated magnesium-containing granulated fertilizer finished product prepared by the embodiment 1 of the invention as a test sample:

placing a stainless steel wire test sieve with the diameter of 200mm and the inner diameter of a sieve hole of 2.0-2.5mm in a plastic basin with the diameter of 350mm upside down, adding a proper amount of water to ensure that the test sieve is completely immersed in the water, ensuring that the water surface is slightly higher than the test sieve by about 10mm, immersing 3-5 samples (about 0.1-0.3g) on the test sieve, starting timing until the samples are completely disintegrated and dissolved and pass through the sieve, and stopping timing, wherein the time is disintegration time limit. Referring to table 1, 5 times of tests are respectively performed, and it is known from the test results that the average disintegration time is 22S, and the effect of rapid disintegration is achieved, and the test data are shown in table 1:

TABLE 1 disintegration time limit of magnesium-containing granular fertilizer in Water

Name (R)	Test 1	Test 2	Test 3	Test 4	Test 5	Average
							Disintegration time/S	24	21	22	23	20	22

Test example 2: evaluation of Effect of Fertilizer

The fertilizer efficiency of the disintegrated magnesium-containing granulated fertilizer prepared by the invention is measured by the test, wherein the disintegrated magnesium-containing granulated fertilizer finished product prepared by the embodiment 3 of the invention is used as a test sample for the test:

the rice, peanut and sesame of field crops, the orange, banana, pineapple and tobacco of economic crops and the potato and tomato of vegetables are crops which need more magnesium. In 2017, a tobacco field planted by a farmer in the southern Ping area of Fujian province is selected as a fertilizer efficiency test base, 60kg of compound fertilizer NPK (15-15-15) is applied to each mu, and the disintegration type magnesium-containing granular fertilizer and the traditional disintegration type magnesium fertilizer are applied as base fertilizers, wherein the base fertilizers are 25kg per mu. The soil is sandy loam, the pH value is 5.48, and alkaline hydrolysis nitrogen: 78.63mg/kg, fast-acting phosphorus: 35.17mg/kg, quick-acting potassium: 53.77mg/kg, the exchange magnesium content is 69.88 mg/kg. The experiment was set up with 3 treatments: (1) NPK, (2) NPK + traditional disintegration type magnesium fertilizer, and (3) NPK + disintegration type magnesium fertilizer of the invention. The field treatment is consistent during the test period, and the variety to be tested is Yunyan 85. And testing the magnesium content of the tobacco leaves, the agronomic index, the influence on the soil fertility and the like in different periods.

The applied disintegrating magnesium-containing granular fertilizer can be immediately disintegrated or dissolved when meeting water or tide after being applied into soil, can meet the requirement of the whole growth cycle of tobacco on nutrients, has good growth promoting effect, is particularly beneficial to the growth of upper leaves, and has robust plants without the phenomenon of magnesium deficiency. The applied traditional disintegrating magnesium fertilizer has the following test data shown in table 2, wherein the disintegration time is long, so that the early-stage nutrient release is too slow, the long-acting property is poor, the later-stage leaf magnesium content is reduced, the nutrient absorption is unbalanced, the whole leaf is yellow and white, and the plant is lack of magnesium:

TABLE 2 magnesium content of tobacco leaves corresponding to different fertilization treatments

The yield of the applied disintegrated magnesium granular fertilizer is increased by 36.27 percent, the first-class smoke proportion is 34.19, the yield increasing effect is obvious, the economic yield can be improved compared with the traditional disintegrated magnesium fertilizer, and the test data is shown in table 3:

TABLE 3 agronomic indices for different fertilization treatments of tobacco

Taking soil of a soil layer of 20cm, testing the content of exchanged magnesium in the soil and the pH value in the soil on different days after fertilization respectively, and obtaining the following results through tests: the applied disintegrating magnesium-containing granular fertilizer has the advantages that due to the long-acting slow release effect, nutrients are not easy to lose, the content of exchanged magnesium in soil is highest, the growth of tobacco is facilitated, meanwhile, the pH value change of the soil is obvious, the fertilizer has the function of conditioning the soil, and the test data are shown in table 4 and figure 4:

TABLE 4 Effect of different fertilisation treatments on soil fertility

The above list is merely illustrative of the present invention and should not be construed as limiting the scope of the present invention, and all designs identical or similar to the present invention are within the scope of the present invention.

Claims

1. The disintegration type magnesium-containing granulated fertilizer is characterized in that the magnesium-containing fertilizer granules comprise the following raw materials in parts by mass: 60-90 parts of magnesium-containing raw material; 10-40 parts of a balling assistant; 12-20 parts of organic acid solution with the mass concentration of 5% -20%;

the magnesium-containing raw material comprises the following components: brucite powder (magnesium is calculated by MgO), and the MgO mass content is more than or equal to 64 percent; dolomite powder (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 21 percent;

the auxiliary agent for balling consists of magnesium sulfate monohydrate and magnesium oxide, or consists of magnesium sulfate monohydrate and magnesium carbonate; wherein, the magnesium sulfate monohydrate (magnesium is calculated as MgO), and the MgO mass content is more than or equal to 29 percent; magnesium oxide (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 85 percent; magnesium carbonate (magnesium is calculated by MgO), and the mass content of MgO is more than or equal to 35 percent;

the organic acid solution is any one or more of formic acid, acetic acid, oxalic acid, propionic acid, butyric acid and dimeric aspartic acid;

the disintegration type magnesium-containing granulated fertilizer is prepared by the following method:

(1) preparing raw materials: respectively measuring a magnesium-containing raw material and a balling assistant according to the raw material proportion; dissolving organic acid in water to prepare an organic acid solution with the mass concentration of 5-20%;